The objective of the proposed research is to understand the cellular mechanisms that control the growth and androgen-dependent functions of prostate epithelial cells. Androgen-dependent proteins from normal prostate and the R3327 adenocarcinoma will be identified in vivo by SDS-PAGE analysis of extracts from normal, castrated and castrated-testosterone-treated rats. Androgen-dependent proteins will be isolated from normal and tumor tissue, specific antisera will be prepared and an immunoassay established for androgen-dependent proteins in cultured cells or the culture medium. The best methods, conditions, matrix, nutritive and regulatory factors required for growth and maintenance of androgen-responsiveness of normal rat prostate epithelial cells will be established. Androgen-responsive cells will be indentified by the presence of androgen-dependent proteins. For comparative study, androgen-responsive continuous cell line models will be established from the Dunning R3327 rat prostatic adenocarcinoma by animal-to-culture-to-animal alternate passage and cell cloning techniques. The extracellular requirements for growth and androgen-responsiveness of normal and tumor-derived prostatic epithelial cells will be compared.